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Drop unused factor levels in a subsetted data frame
...tion, a new data frame is created. However, the factor variable retains all of its original levels, even when/if they do not exist in the new dataframe.
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How to set timeout on python's socket recv method?
...lect() to wait until data is available or until the timeout occurs. Only call recv() when data is actually available. To be safe, we also set the socket to non-blocking mode to guarantee that recv() will never block indefinitely. select() can also be used to wait on more than one socket at a time...
Xcode Command /usr/bin/codesign failed with exit code 1 : errSecInternalComponent
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Open Keychain Access, then in the File menu select Lock All Keychains.
Then go back to Xcode and clean and rebuild. It will prompt you for your password again to unlock the keychain.
After this, assuming you have no other compile issues, it will succeed!
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A definitive guide to API-breaking changes in .NET
... information as possible regarding API versioning in .NET/CLR, and specifically how API changes do or do not break client applications. First, let's define some terms:
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How to run Visual Studio post-build events for debug build only
...figuration)" == "Debug" worked for me. BTW, if you want to do something in all other configs, use if NOT "$(Configuration)" == "Debug".
– Ralf Hundewadt
Jun 29 '17 at 9:46
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Linux/Unix command to determine if process is running?
...s arg vector. Any such approach is doomed to fail sooner or later (you actually admit to that yourself, by saying that more checks are needed). I've added my own recommendation in a separate answer.
– peterh
Oct 3 '13 at 10:41
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Difference between wait() and sleep()
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A wait can be "woken up" by another thread calling notify on the monitor which is being waited on whereas a sleep cannot. Also a wait (and notify) must happen in a block synchronized on the monitor object whereas sleep does not:
Object mon = ...;
synchronized (mon) {
...
Read String line by line
...s = myString.split(System.getProperty("line.separator"));
This gives you all lines in a handy array.
I don't know about the performance of split. It uses regular expressions.
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What is the easiest way to disable/enable buttons and links (jQuery + Bootstrap)
...ple piece of jQuery code to target anchor tags with the disabled class to call event.preventDefault():
$('body').on('click', 'a.disabled', function(event) {
event.preventDefault();
});
We can toggle the disabled class by using toggleClass():
jQuery.fn.extend({
disable: function(state) {
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Why create “Implicitly Unwrapped Optionals”, since that implies you know there's a value?
...e two main reasons that one would create an Implicitly Unwrapped Optional. All have to do with defining a variable that will never be accessed when nil because otherwise, the Swift compiler will always force you to explicitly unwrap an Optional.
1. A Constant That Cannot Be Defined During Initializ...